BMW M30B30

BMW M30B30 Engine

  1. Specifications
  2. Overview, problems
  3. Performance tuning

BMW M30B30 engine specs

Manufacturer Munich Plant
Also called BMW M30
Production 1971-1994
Cylinder block alloy Cast-iron
Configuration Straight-6
Valvetrain SOHC
2 valves per cylinder
Piston stroke, mm (inch) 80 (3.15)
Cylinder bore, mm (inch) 89 (3.50)
Compression ratio 9.0
Displacement 2986 cc (182.2 cu in)
Power output 135 kW (184 HP) at 5,800 rpm
138 kW (188 HP) at 5,800 rpm
145 kW (197 HP) at 5,800 rpm
Torque output 255 Nm (188 lb·ft) at 3,500 rpm
260 Nm (192 lb·ft) at 4,000 rpm
275 Nm (203 lb·ft) at 4,000 rpm
Redline 6,400
HP per liter 61.6
Fuel type Gasoline
Weight, kg (lbs) 135 (300)
Fuel consumption, L/100 km (mpg)

for E32 730i
16.3 (14.4)
7.6 (31)

11.0 (21.4)
Turbocharger Naturally aspirated
Oil consumption , L/1000 km
(qt. per miles)
up to 1.0
(1 qt. per 750 miles)
Recommended engine oil 5W-30
Engine oil capacity, L (qt.) 5.75 (6.05)
Oil change interval, km (miles) 5,000-10,000
Normal engine operating temperature, °C (F) ~90 (195)
Engine lifespan, km (miles)
-Official information

400,000+ (250,000)
Tuning, HP
-Max HP
-No life span loss


The engine is installed in BMW 530i E34/E12
BMW 630 E24
BMW 730i E32/E23
BMW E3 3.0
BMW E9 3.0

BMW M30B30 engine reliability, problems and repair

In the period from the early 70’s and late 80’s, a BMW with an index of 30 and 30i equipped with an engine M30B30. It is the big 6-cylinder motor with 3 liter capacity. This engine uses a cast iron engine block, the same as M30B28, but with a bore of 89 mm. Crankshaft has a stroke of 80 mm, rod length – 135 mm, piston compression height – 42.8 mm.
The cylinder head is simple – SOHC 8V without hydraulic lifters. Specs of the camshaft M30B30: duration 260 deg, lift 7.4 mm. The stock size of fuel injectors of BMW M30B30 engines is 192 cc/min. The camshaft is set in motion by timing chains. The fuel system was both carburetor, and injector. Carburetor M30B30 produced till 1979, and injector M30B30 – throughout all period of production.
The M30B30 Carb engine appeared together with the injector version in 1971 and had compression ratio 9:1. Its power is 180 HP at 6,000 rpm. Injector M30B30 equipped with Bosch D-Jetronic. Compression ratio of such motor 9.5:1 that allowed to get 200 horsepower at 5,500 rpm. Since 1976 Solex Zenith 35/40 INAT carburetors replaced on Solex DVF-4A1. Power of the modified engines increased to 184 horsepower at 5,800 rpm. In 1979 the M30B30 Carb replaced by fuel injection M30B28. In 1975 injector M30B30 were modified: compression ratio decreased to 9:1 and used Bosch L-Jetronic. Power decreased to 195 HP at 5,800 rpm. In 1986 the M30B30 began to install on BMW 730i E32. Such motor had compression ratio 9.2:1 and 197 horsepower at 5,800 rpm. Produced a version with a catalytic converter with compression ratio 9:1. Power of such engine is 188 HP at 5,800 rpm.

Further M30B32 and M30B35 based on 3 liter M30 such as other famous series engines M30. Together with the BMW 730i E32 production of M30B30 stopped in 1994. Instead of it began to produce BMW 730i E38 with new 3 liter M60B30.

BMW M30B30 engine problems and malfunctions

The main disadvantages, problems and malfunctions of 3-liter M30 don’t differ from M30B35. You can read more about it just by clicking HERE.

BMW M30B30 engine tuning

M30B30 stroker

You can make M30B35 from M30B30. For this you need to buy pistons, the crankshaft and ECU from M30B35, and also to increase diameter of cylinders to 92 mm. Rods can be leave stock. It give about 15-20 additional horsepower. If the cylinders leave stock and install only the crankshaft with 86 mm stroke and the pistons from M30B32, you will get a 3.2 liter displacement. It will give only about 10 horsepower.
Increasing capacity to 3.5 liter, it is better to buy M30B35 head with enlarged inlet valves. More power you can get if you buy a Schrick camshafts 284/280 deg, valve springs, reinforced rocker arms, cold air intake, straight pipes exhaust system. It give about 50-60 additional horsepower. Also it is possible to building a turbo project from M30B30 by analogy with M30B35. Learn about it a little more HERE.